1. Field of the Invention
The present invention relates in general to oilfield applications involving the fluid treatment of wellbores. More specifically, the invention relates to systems for controlling the distribution of fluid to one or more wellbores.
2. Description of the Related Art
Hydraulic fracturing is one type of fluid treatment for a wellbore in which a fluid is pumped into a subterranean geologic formation through the wellbore. The fluid is provided at a sufficient pressure to fracture the geologic formation, thus facilitating the recovery of hydrocarbons from the formation. Often, the wellbore is subjected to multiple fluid treatment cycles in which fluid is provided and subsequently extracted. Between treatment cycles, down-hole operations may be carried out in the wellbore to install equipment or to evaluate the effectiveness of the most recent treatment cycle.
Generally between treatment cycles, pumping equipment is disconnected from the wellbore and connected to a second wellbore such that the fluid treatment may be carried out on the second wellbore concurrently with other down-hole operations on the first wellbore. Because these connections and disconnections consume a considerable amount of time and manpower, some manifolds have been developed that enable selective pumping to one or more wellbores. These manifolds are typically designed and constructed remotely for use in a particular application to accommodate a particular number of wellbores. These manifolds are less effective when used for subsequent operations at a well site with a different number of wellbores. Also, these manifolds are not configurable at the well site to accommodate changing conditions and needs. For example, when a sufficient number of treatment cycles have been performed on some of the wellbores coupled to the manifold, and additional treatment cycles are intended for other wellbores coupled to the manifold, only a portion of the manifold is used. This results in significant costs for an operator who must keep an inventory sufficient to accommodate unused portions of manifolds.